1. Field of the Invention
This invention relates to a face image recognition apparatus which recognizes the face image of a person for security management or the like and a passage control apparatus which controls passage of a passer by use of the face image recognition apparatus.
2. Description of the Related Art
Conventionally, in the face image recognition apparatus, a face image obtained by photographing the face of a person is collated with previously registered face images to perform the face image recognition process. However, in the face image recognition apparatus, the person recognition rate is lowered by factors such as a variation in the face itself, for example, a variation in the hair style, beard or makeup or the presence or absence of glasses, or a variation in the face image due to a variation in the standing position of the person.
A method for suppressing a lowering in the person recognition rate is proposed in Jpn. Pat. Appln. KOKAI Publication No. 11-167632. In Jpn. Pat. Appln. KOKAI Publication No. 11-167632, a method for re-registering the face image when the person recognition rate is lowered to some extent is disclosed. Further, in Jpn. Pat. Appln. KOKAI Publication No. 11-167632, a method for registering a new reference feature amount obtained by combining a reference feature amount for each face image of each of persons previously registered with a feature amount obtained from a photographed (input) face image is disclosed.
In Jpn. Pat. Appln. KOKAI Publication No. 11-167632, if the person recognition rate is lowered, that is, if the similarity between the feature amount obtained from an input image and each of reference feature amounts previously registered is lowered, a reference feature amount is newly registered or re-registered by use of the input image. For example, each time a person who changes his hair style every day is recognized, registration information (reference feature amount) is updated or newly registered. By repeating the above re-registration or new registration, there occurs a possibility that no difference is made between the registration information of each person and that of another person. As a result, the recognition rate may be lowered.